Copper grease use.

[Tiiimmmaaayyyy]

I use copaslip on the caliper bolts, torqued them up as per the manual figures. Never had a problem with over tightening or stripping threads before.

 

[Gaffa22]

if it does happen it can be expensive, I never grease caliper bolts and I've never had one seize and I ride all weathers.
Caliper bolts should actually be loctited in not greased, so what could be worse than seizing is the bolts falling out, that could cause a brown pants moment or worse still a collision

 

[Tiiimmmaaayyyy]

In 25 yrs of riding they haven't fell out or broken yet, I think it'll be alright :tennis:

 

[pof]

Ive only ever used a torque wrench twice and both times it snapped a bolt. Never using one again.

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[Gaffa22]

In 25 yrs of riding they haven't fell out or broken yet, I think it'll be alright :tennis:

I'm sure you will,
a mate of mine did crash at snetterton cos his caliper fell off but then I'm not sure he had actually fitted the bolts, he only got as far as the first corner after changing the front wheel.

 

[stuartb]

if it does happen it can be expensive, I never grease caliper bolts and I've never had one seize and I ride all weathers.
Caliper bolts should actually be loctited in not greased, so what could be worse than seizing is the bolts falling out, that could cause a brown pants moment or worse still a collision

You sure about loctite on caliper bolts Gaffa ? Ive never seen that in any workshop manual ?

Just managed to get logged into the program. Its a program that we have for calculating tightening values for pipe flanges. Had a look to see if i could make any sense of what the % difference is, but there isn't an option for no grease. The friction coefficient for copper based greases varies between 0.09 for copperslip (not to be mixed up with copaslip which is 0.12) and copper ease which is 0.14. Just the difference between the different greases make a huge difference to the final torque of the bolt Approx 30 %.
To be able to work out what percentage to subtract from the original torque, you'd need to know what the original coefficient is, which i think varies depending on the thread size, contact area of the threads, and what the materials are of the 2 threads.

I'm far from an expert in it. Thats why we have a computer program to work it out for us

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[Mick753]

I think this is one of them subjects that often gets overlooked by your average bobble hat mechanic let alone the back street garages as it only generally tends to be people that have studied engineering now that actually get taught this I reckon, I certainly got taught it way back when I got into mechanical engineering but it's actually rare I ever hear anyone other talking about.

I used to have a really good link that was put together by someone that had taken the time and effort to test and compile a full list of all the different torque figures and reduction percentages for bolts that have had different greases applied to them but for the life of me I can't find it

However this very American one does explain it in brief terms, the fact is that if you apply grease you reduce torque in pretty much all cases, but in terms of bikes and warranties, if it doesn't state for the bolt to be greased in the manual I wouldn't bother with it

http://www.raskcycle.com/techtip/webdoc14.html

 

[Gaffa22]

You sure about loctite on caliper bolts Gaffa ? Ive never seen that in any workshop manual ?

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Well I have removed plenty that were loctited in from new.
just for the record I was trained as a motor engineer and worked as a mechanic.

 

[stuartb]

Well I have removed plenty that were loctited in from new.
just for the record I was trained as a motor engineer and worked as a mechanic.

So was I, just to clarify workshop manuals for bikes not any other vehicle... I dont recall seeing a requirement for loctite...

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[stuartb]

Thats not to say it doesnt exist...

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[stuartb]

I think this is one of them subjects that often gets overlooked by your average bobble hat mechanic let alone the back street garages as it only generally tends to be people that have studied engineering now that actually get taught this I reckon, I certainly got taught it way back when I got into mechanical engineering but it's actually rare I ever hear anyone other talking about.

I used to have a really good link that was put together by someone that had taken the time and effort to test and compile a full list of all the different torque figures and reduction percentages for bolts that have had different greases applied to them but for the life of me I can't find it

However this very American one does explain it in brief terms, the fact is that if you apply grease you reduce torque in pretty much all cases, but in terms of bikes and warranties, if it doesn't state for the bolt to be greased in the manual I wouldn't bother with it

http://www.raskcycle.com/techtip/webdoc14.html

Thats handy Mick... and interesting.. thanks

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[Gaffa22]

So was I, just to clarify workshop manuals for bikes not any other vehicle... I dont recall seeing a requirement for loctite...

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You may well be right Stuart, I thought I had seen in a manual but can't remember which one.

either way I'd rather put loctite on them than copperslip,

 

[stuartb]

Cool were probably both right...or wrong lol

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[Gaffa22]

Cool were probably both right...or wrong lol

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Yes we probably are

i dont get get the fascination with copper grease there are much better modern alternatives that don't make so much mess and without the risk of oxidation with disimilar metals.

 

[stuartb]

Haha.. its an age thing. I still use the old trade name Copaslip which is actually trademarked... A snickers is still a Marathon peanut M and Ms are of course...peanut treats... in my head anyhow

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[HPlogger]

I've always used loctite on brake caliper retaining bolts and have always cleaned the old loctite off after removed before applying new loctite and torqued to manufacture's recommendation.

In dry use only I've also applied copper grease to the retaining pin where pads holes are and on the thread.

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[Gaffa22]

Haha.. its an age thing. I still use the old trade name Copaslip which is actually trademarked... A snickers is still a Marathon peanut M and Ms are of course...peanut treats... in my head anyhow

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yes I remember the old days too copaslip and duck oil the two most used consumables in the garage, and yes why do they feel the need to change the name of chocolate bars

 

[JimmyMac]

yes I remember the old days too copaslip and duck oil the two most used consumables in the garage, and yes why do they feel the need to change the name of chocolate bars

I have often wondered if coconuts would ever be renamed?

Then I thought "Aye, they're bounty".

Ill get my coat, lol.

JimmyMac

 

[Gaffa22]

I have often wondered if coconuts would ever be renamed?

Then I thought "Aye, they're bounty".

Ill get my coat, lol.

JimmyMac

LOL very good Jimmy

 

[HPlogger]

Oh well, this has turned into hardly any help (apart from kennybush answeres). Using copper grease does prolong the life of capable easily mechanical separation even in wet (the copper grease can be sealed within confinements of some assemblies).

I'll simply ask my engineer father!

Thanks.